Merge pull request #152 from mrodrig/fix-151

Fix #151

Author: mrodrig

package-lock.json

@@ -5,7 +5,7 @@
     },
     "name": "json-2-csv",
     "description": "A JSON to CSV and CSV to JSON converter that natively supports sub-documents and auto-generates the CSV heading.",
-    "version": "3.7.1",
+    "version": "3.7.2",
     "repository": {
         "type": "git",
         "url": "https://github.com/mrodrig/json-2-csv.git"

package.json

@@ -216,11 +216,15 @@ function unwindItem(accumulator, item, fieldPath) {
     const valueToUnwind = path.evaluatePath(item, fieldPath);
     let cloned = deepCopy(item);
 
-    if (Array.isArray(valueToUnwind)) {
+    if (Array.isArray(valueToUnwind) && valueToUnwind.length) {
         valueToUnwind.forEach((val) => {
             cloned = deepCopy(item);
             accumulator.push(path.setPath(cloned, fieldPath, val));
         });
+    } else if (Array.isArray(valueToUnwind) && valueToUnwind.length === 0) {
+        // Push an empty string so the value is empty since there are no values
+        path.setPath(cloned, fieldPath, '');
+        accumulator.push(cloned);
     } else {
         accumulator.push(cloned);
     }

src/utils.js

@@ -30,6 +30,7 @@ const fs = require('fs'),
         {key: 'quotedEmptyFieldValue', file: '../data/csv/quotedEmptyFieldValue.csv'},
         {key: 'csvEmptyLastValue', file: '../data/csv/csvEmptyLastValue.csv'},
         {key: 'unwind', file: '../data/csv/unwind.csv'},
+        {key: 'unwindEmptyArray', file: '../data/csv/unwindEmptyArray.csv'},
         {key: 'unwindWithSpecifiedKeys', file: '../data/csv/unwindWithSpecifiedKeys.csv'},
         {key: 'localeFormat', file: '../data/csv/localeFormat.csv'},
         {key: 'invalidParsedValues', file: '../data/csv/invalidParsedValues.csv'}

test/config/testCsvFilesList.js

@@ -23,6 +23,7 @@ module.exports = {
     quotedEmptyFieldValue: require('../data/json/quotedEmptyFieldValue'),
     csvEmptyLastValue: require('../data/json/csvEmptyLastValue'),
     unwind: require('../data/json/unwind'),
+    unwindEmptyArray: require('../data/json/unwindEmptyArray'),
     localeFormat: require('../data/json/localeFormat'),
     invalidParsedValues: require('../data/json/invalidParsedValues')
 };

test/config/testJsonFilesList.js

@@ -0,0 +1,4 @@
+_id.$oid,data.category,data.options
+5cf7ca3616c91100018844af,Computers,
+5cf7ca3616c91100018844bf,Cars,Supercharger
+5cf7ca3616c91100018844bf,Cars,Turbocharger

test/data/csv/unwindEmptyArray.csv

@@ -0,0 +1,10 @@
+[
+  {
+    "_id": {"$oid": "5cf7ca3616c91100018844af"},
+    "data": {"category": "Computers", "options": []}
+  },
+  {
+    "_id": {"$oid": "5cf7ca3616c91100018844bf"},
+    "data": {"category": "Cars", "options": ["Supercharger", "Turbocharger"]}
+  }
+]

test/data/json/unwindEmptyArray.json

@@ -415,6 +415,16 @@ function runTests(jsonTestData, csvTestData) {
                 });
             });
 
+            it('should handle unwinding empty array values when specified', (done) => {
+                converter.json2csv(jsonTestData.unwindEmptyArray, (err, csv) => {
+                    if (err) done(err);
+                    csv.should.equal(csvTestData.unwindEmptyArray);
+                    done();
+                }, {
+                    unwindArrays: true
+                });
+            });
+
             it('should unwind array values when specified', (done) => {
                 converter.json2csv(jsonTestData.unwind, (err, csv) => {
                     if (err) done(err);